Field of the Invention
Embodiments of the present invention relate to an organic light-emitting element, and more particularly, to an organic light-emitting array, which prevents lateral current leakage of sub-pixels by changing the structure thereof, and an organic light-emitting display device using the same.
Discussion of the Related Art
Recently, as the information age has fully arrived, the field of displays that visually display electrically conveyed information signals has developed rapidly. In response to this, various kinds of flat panel display devices having excellent characteristics, such as a small thickness, a low weight, and low power consumption, have been developed and have rapidly replaced existing cathode ray tubes (CRTs).
Representative examples of such flat panel display devices may include a liquid crystal display (LCD) device, a plasma display panel (PDP) device, a field emission display (FED) device, and an organic light-emitting display (OLED) device.
Among these, the organic light-emitting display device is considered a competitive application because it does not require a separate light source and enables realization of a compact device design and vivid color display.
The organic light-emitting display device includes self-luminous elements, such as organic light-emitting elements, provided in sub-pixels, and performs display via operation of the organic light-emitting elements on a per sub-pixel basis. In addition, the organic light-emitting elements may be used in a lighting apparatus because they are self-luminous elements, in addition to the display device, and thus the development of organic light-emitting elements has recently been in the spotlight in the lighting industry. In addition, because the organic light-emitting elements require no separate light source unit, they are also advantageously used in a flexible display device or a transparent display device.
Meanwhile, such an organic light-emitting element includes an organic emission layer between an anode and a cathode. In addition, electrons and holes are respectively injected into the organic emission layer from the anode and the cathode, and excitons are produced in the organic emission layer via combination of the electrons and holes. Then, when the produced excitons fall down or move from the excited state to the ground state, light is generated from the organic light-emitting element.
Meanwhile, the organic light-emitting display device includes an organic light-emitting array, which includes, for example, red, green and blue sub-pixels for the display of various colors. In addition, although the organic light-emitting array may be configured in various forms, a tandem type has recently been proposed, in which an anode is formed on a substrate for each sub-pixel, and subsequently a thin organic layer including an organic emission layer and a cathode are formed on an entirety of an array area.
However, in the instance of the tandem type, there occurs current leakage between neighboring sub-pixels since the thin organic layer between the anode and the cathode is provided over the entire array area.
Hereinafter, the problem of a conventional organic light-emitting array in an organic light-emitting display device will be described.
FIG. 1 is a schematic cross-sectional view illustrating a current leakage phenomenon that occurs at the boundary of neighboring sub-pixels of a related art organic light-emitting array.
As illustrated in FIG. 1, in the related art organic light-emitting array, an anode 11 is provided on a substrate 10 for each sub-pixel, and a bank 12 is located to overlap the respective anodes 11 of neighboring sub-pixels in order to define an emission portion. In addition, without distinguishing between the emission portion and a non-emission portion, a thin organic layer 13 is formed on the anode 11 and the bank 12, and a cathode 14 is formed on the thin organic layer 13.
Here, the thin organic layer 13 is an organic semiconductor, and functions as a dielectric substance of an organic light-emitting diode in each sub-pixel by causing vertical current to flow between the anode 11 and the cathode 14. However, since the thin organic layer 13 is also provided on the bank 12 between the neighboring sub-pixels and is connected to the respective sub-pixels, the upwardly transferred current may flow laterally to the neighboring sub-pixels, as illustrated in FIG. 1, causing lateral current leakage.